Notes of Ch 6 Major Landforms of the Earth| Class 6th Geography

Notes of Chapter 6 Major Landforms of the Earth Class 6th Geography

• The surface of the earth varies from one place to another. The main landforms are; mountains, plateau and plains.

• There are two processes which lead to formation of different landforms:

→ Internal process

→ External process

Internal Process

• The movement of earth’s surface results in internal process.

• The internal process results in a portion of the earth’s surface getting elevated or getting sunk.

External Process

• Continuous wearing down and rebuilding of the earth’s surface is the result of external process.

Erosion

• Removal of materials is called erosion.

• Erosion results in lowering of the earth’s surface.

• It is carried out by various agents; like wind and water.

Deposition

• Deposition of materials results in rebuild of the earth’s surface. It also results in the surface getting elevated. Wind and water are the main agents of deposition.

Glacier

• Permanently frozen rivers of ice are called glaciers. Glaciers are found in some of the very high mountains.

Mountains

• A mountain is the natural elevation of the earth’s surface.

• It may be narrow at top and broad at the base.

• The elevation of mountain is considerably more than that of surrounding area.

• Temperature reduces with increase in altitude. Due to this, very high mountains are usually covered with snow.

Population at Mountains

• Because of steep slopes, less amount of land is available for farming on mountains. This is also difficult to build houses on steep slopes. Hence, less number of people lives on the mountains.

Mountain Range

• When mountains are arranged in a line, then it is called a mountain range.

• Some of the mountain systems contain ranges spread over hundreds of kilometres.

Types of Mountains

• There are three types of mountains, viz. fold mountains, Block Mountains and volcanic mountains.

→ Fold Mountains: When a tectonic plate gets pressure from two sides, it gets folded. Some of its portion becomes elevated and forms the mountains. The depressions form the valleys. The Himalayas, The Andes and the Alps are examples of Fold Mountain.

→ Block Mountains: When large areas are broken and displaced vertically, Block Mountains are formed. In this case, the uplifted blocks are called horsts.

→ Volcanic Mountains: A mountain formed due to volcanic activity is called Volcanic Mountain. Examples of Volcanic Mountains are; Mt. Kilimanjaro and Mt. Fujiyama.

Importance of Mountains

• Mountains are rich sources of water. Many important rivers originate from glaciers on mountains.